CN113126043A

CN113126043A - Method for improving testability of Doppler radar

Info

Publication number: CN113126043A
Application number: CN201911397862.1A
Authority: CN
Inventors: 贾兴豪; 邓广宁; 薛崇峰; 林峰
Original assignee: Beijing Huahang Radio Measurement Research Institute
Current assignee: Beijing Huahang Radio Measurement Research Institute
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2021-07-16
Anticipated expiration: 2039-12-30
Also published as: CN113126043B

Abstract

The invention relates to a method for improving testability of a Doppler radar, which belongs to the technical field of speed measuring radars and solves the problems that the appearance of the conventional Doppler radar is not conformal to a carrier, the required installation space is large, and the installation precision is poor; the miniaturized Doppler radar has the problems of inconvenient test and poor testability. The method for improving the testability of the Doppler radar comprises the steps of determining a conformal structure of the Doppler radar, performing modular design and extension test on radar extensions, arranging the extensions in an installation mode, sealing an opening in the upper end of the conformal structure after the extensions of the radar are installed, completing the assembly of the miniaturized Doppler radar, and performing complete machine test. The invention improves the testability and the test reliability of the Doppler radar.

Description

Method for improving testability of Doppler radar

Technical Field

The invention relates to the technical field of speed measuring radars, in particular to a method for improving testability of a Doppler radar.

Background

The existing aircrafts are various and comprise airplanes, unmanned planes, aerospace equipment, electronic equipment and the like. The Doppler radar is used for providing navigation information such as three-axis speed and the like for a satellite navigation system so as to realize a navigation/Doppler combined navigation function. In the working process, on the basis of the Doppler effect, speed information is obtained based on the frequency difference between electromagnetic waves radiated by the radar and echoes, wherein the frequency difference is Doppler frequency shift. When the parameters of the radar are determined, the doppler frequency fd is only related to the velocity of the movement of the radar's carrier relative to the ground. And each component of the radar carrier velocity vector measured by the beam antenna is used for navigation.

For aircraft, there are strict requirements on the shape, size, aerodynamic properties, etc. With the development of technology and the demand of indexes, strict requirements are put on the size and weight of the equipment, and the miniaturization design is very important.

Because the aircraft service environment is harsh, the appearance of current doppler radar is mostly the rectangle structure, and does not conform with the carrier, and the installation space that needs is great, and the installation accuracy is low, seriously influences the performance of radar and the wholeness ability of carrier. In addition, the conventional doppler radar cannot be exchanged once installed, and is not maintainable or has poor maintainability. The existing radar is large in size due to abundant installation space, and the existing radar can be unpacked to perform extension testing when being tested. With the increasing increase of the functions of the aircraft, the equipment installation space on the aircraft has more and more technical value, and higher requirements on the scientific utilization of the space are also provided. In order to reduce the size and weight of the doppler radar device and to achieve the miniaturization of the external shape, the speed measurement doppler radar needs to be miniaturized, but the miniaturized doppler radar is inconvenient to perform performance test after being installed due to the small size, and therefore, a method for improving the testability of the doppler radar is urgently needed to be provided.

Disclosure of Invention

In view of the foregoing analysis, the present invention provides a method for improving the testability of a doppler radar, so as to solve one of the following problems: (1) the shape of the existing Doppler radar is not conformal to the carrier; (2) the required installation space is large, and the installation precision is poor; (2) the testability of the Doppler radar which is conformal to the carrier and small in installation space is guaranteed, and the problem that the test of the miniaturized Doppler radar is inconvenient is solved.

In order to solve the technical problems, the invention provides a method for improving the testability of a Doppler radar, which comprises the following specific technical scheme:

a method of improving the testability of a doppler radar having a structure conformal to a mounting surface, each extension of the doppler radar being disposed within a cavity of the conformal structure, the method comprising the steps of:

(1) determining a conformal structure of the Doppler radar according to the size of a scene where the Doppler radar is suitable;

(2) according to the determined conformal structure, performing modular design and extension test on the radar extension;

(3) arranging the modularized antenna extension machine qualified in the test at the bottom of the conformal structure;

(4) arranging a modular filter, a power supply extension and a transceiving component which are qualified in test above the antenna extension;

(5) arranging the receiving extension, the wiring extension and the signal processing extension which are qualified in the test in the uppermost space of the conformal structure;

(6) after the installation of each extension of the radar is finished, sealing an opening at the upper end of the conformal structure to finish the assembly of the miniaturized Doppler radar;

(7) and (6) carrying out a complete machine test.

Further, in the step (3), the antenna extension set is a passive extension set, and is not powered on, and is placed at the bottommost layer.

Further, in the step (4), the filter, the power extension and the transceiver module are arranged in the same layer above the antenna extension to form an intermediate layer, and the filter and the power extension are arranged at positions close to the external interface of the radar.

Further, in the step (5), the receiving extension, the wiring extension and the signal processing extension are arranged in the uppermost space of the conformal structure at the upper part of the middle layer to form the uppermost layer, and the signal processing extension is arranged at the outermost position.

Further, in the step (5), the extension cord uses a single printed board to connect signals between the signal processing extension, the transceiver module and the radar console.

Further, in the step (7), the radar main body composed of all the extensions in the conformal structure is subjected to the overall test.

Further, in step (1), the conformal structure includes a main frame and an upper cover plate, the main frame is a tubular structure with openings at two ends, the radome and the upper cover plate are respectively arranged at two ends of the tubular structure, and both the main frame and the radome are conformal with the installation surface.

Further, the radome and the main body frame are in lap joint.

Further, in the step (2), each extension adopts a box structure to realize modularization.

Furthermore, the radar extension set comprises an antenna extension set, a transceiving component, a receiving extension set, a signal processing extension set, a wiring extension set and a power supply extension set.

Furthermore, the internal cavity of the main body frame of the conformal structure is of a multilayer structure, and each layer of cavity structure is divided into a plurality of partitions according to the structure and the number of the arranged extension box bodies. Specifically, the internal cavity of the main body frame is of a 3-layer structure and comprises an upper layer, a middle layer and a lower layer, and the antenna extension occupies the lower layer independently; the filter, the power extension and the transceiving component are positioned in the middle layer; the receiving extension, the wiring extension and the signal processing extension are positioned on the upper layer. More specifically, the signal processing extension is arranged in the one side region on upper strata alone, it is regional with the opposite side of extension of working a telephone switchboard parallel arrangement on upper strata to receive the extension, the power extension is located between wave filter and the receiving and dispatching subassembly, the receiving and dispatching subassembly is located the below of extension of working a telephone switchboard and signal processing extension, the power extension is located the below of the receipt extension of upper strata, the lower surface of receiving the extension is equipped with the cavity structure, the extension of working a telephone switchboard is located the cavity structure of the receipt extension between receipt extension and the power extension.

Compared with the prior art, the invention has at least one of the following beneficial effects:

1. based on the consideration of scientific utilization of the installation space of the aircraft, the invention simultaneously considers how to realize the conformity of the Doppler radar and the installation surface, and reduces the required installation space as much as possible, realizes the miniaturization of the Doppler radar (the dimension of the conformal structure can be the following dimension: the length multiplied by the width multiplied by the height is 135mm multiplied by 68mm multiplied by 36.5mm, the dimension of the antenna extension can be the length multiplied by the width multiplied by the height is 114mm multiplied by 47mm multiplied by 9.5mm, the dimension of the transceiving component can be the length multiplied by the width multiplied by the height is 60mm multiplied by 40mm multiplied by 10.8mm, the dimension of the receiving extension can be the length multiplied by the width multiplied by 40mm multiplied by 27mm multiplied by 16.3mm, the dimension of the power supply extension can be the length multiplied by the width multiplied by the height is 31mm multiplied by 20mm multiplied by 9mm, which is 1/3-1/4 mm of the conventional radar size), and ensures the conformity with the installation carrier, the needed miniaturization of the Doppler radar with small installation space, and the testing convenience, And (6) reliability.

2. The Doppler radar has the advantages that the appearance structure of the Doppler radar which is conformal to the aircraft, namely a conformal structure, is adopted, the radar is conformal to the aircraft, and the extension is conformal to the whole machine, so that the structural technical installation precision requirement associated with the navigation technical performance is met, the structural electromagnetic shielding design is realized, the entry of electromagnetic waves can be physically shielded, the problems of aircraft installation and miniaturization are effectively solved, the complexity of hardware equipment is reduced, the testing difficulty is reduced, and the testability of the miniaturized Doppler radar is improved. In addition, the installation precision of the aircraft is guaranteed, and the reliability, maintainability and electromagnetic compatibility of the product are effectively improved.

3. The invention considers the miniaturization characteristic of each extension of the Doppler radar, has higher difficulty in the installation and test process, is different from the Doppler radar with the conventional size, is inconvenient for testing a plurality of single units by the miniaturized Doppler radar, designs the selection of the extension, the form of the extension and the arrangement of the extension, and tests the extension before installation, greatly improves the testability of the miniaturized Doppler radar and can test without opening boxes.

4. The test of the miniaturized Doppler radar installed in the conformal structure can meet the test requirements of the whole process of a design stage, an assembly stage and a flight stage by selecting the extension, the form of the extension and the arrangement of the extension, and testing the extension before delivery by adopting a radio frequency signal source through testing in a simulated assembly state and a simulated flight state; the built-in self-checking test is adopted to finish the test after the delivery and the setting of the Doppler radar, and the testability of the miniaturized Doppler radar is obviously improved.

5. The whole Doppler radar has a compact structure and high integration degree, is favorable for improving the speed measurement precision, reliability and maintainability, and is also convenient for updating and upgrading aircraft loading equipment.

6. According to the layout structure of the Doppler radar, the extension box bodies are stacked and arranged in the inner cavity of the main body frame in an extension stacking mode, so that the overall structure of the Doppler radar is more compact, the integration degree is higher, the speed measurement precision, the reliability and the maintainability are improved, the assembly, the test, the wiring and the maintenance of each extension are facilitated, and the updating of an aircraft are facilitated.

7. The antenna extension is a passive extension, does not need power supply, has very high reliability, basically does not need maintenance after passing the test, and is placed at the lowest layer. The receiving and transmitting component communicates and controls the radio frequency cable and the low frequency cable with the antenna extension and the wiring extension, and the receiving and transmitting component is arranged on the upper layer of the antenna extension to be most beneficial to cable connection and assembly. The power extension, the filter and the wiring extension are close to the radar external interface, the length of cables from the external connector to the filter, the power extension and the wiring extension is shortened, and the cable connection of the wiring extension, the receiving extension, the transmitting-receiving assembly and the signal processing is facilitated. The signal processing extension is a component with the most complex function and the most concentrated electronic circuit of the Doppler radar, is the core for controlling the work of the Doppler radar, is arranged on the outermost side, and can be adjusted by opening the shielding box cover of the extension only by using a screwdriver, thereby being beneficial to the overhaul of the extension; a high-frequency cable for conveniently installing the transceiving component; the front panel of the receiving and transmitting assembly is provided with a notch, and the cable is disassembled and assembled through the notch, so that the whole machine can be conveniently assembled and tested.

8. According to the invention, each extension box body is fixed on the main body frame through the vibration damping structure, each extension box body is provided with the mounting hole for mounting the vibration damping structure, the radar whole machine has the vibration damping function in the vertical direction and the horizontal direction, the extension box body and the main body frame can be prevented from directly colliding through the vibration damping structure, the vibration damage from the mounting surface is obviously attenuated, the influence of vibration on the test is avoided, and the accuracy and the reliability of the Doppler radar test are improved.

In the invention, the technical schemes can be combined with each other to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and drawings.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

FIG. 1 is a schematic flow chart illustrating the improvement of the testability of the Doppler radar according to the present invention;

FIG. 2 is a first cross-sectional view of a Doppler radar in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of an antenna extension of the Doppler radar in the embodiment of the invention;

FIG. 4 is a schematic diagram of an exemplary transceiver module of the Doppler radar;

FIG. 5 is a schematic diagram of the shape of a receiving extension of the Doppler radar in the embodiment of the invention;

FIG. 6 is a block diagram of a receiving extension of the Doppler radar in the embodiment of the present invention;

FIG. 7 is a schematic diagram of the power extension of the Doppler radar in the embodiment of the invention;

FIG. 8 is a schematic view of the installation of the vibration reduction structure of the signal processing extension of the Doppler radar in the embodiment of the present invention;

FIG. 9 is a diagram illustrating a first exemplary Doppler radar according to the present invention;

FIG. 10 is a diagram illustrating a second exemplary Doppler radar according to the present invention;

fig. 11 is a schematic diagram showing an internal structure of a main body frame of the doppler radar in the embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a holder for a Doppler radar according to an embodiment of the present invention;

FIG. 13 is a second cross-sectional view of a Doppler radar in accordance with an embodiment of the present invention;

fig. 14 is an enlarged view of a portion of a region a in fig. 13.

Reference numerals:

1-antenna extension, 2-transceiving component, 3-receiving extension and 3.1-cavity; 3.2-a separator; 3.3 weight reduction grooves; 3.4-through vias; 4-signal processing extension, 5-wiring extension, 6-power supply extension, 7-main body frame, 7.1-convex edge and 7.2-positioning pin hole; 7.3-frame mounting holes; 7.4-test interface; 7.5-limiting structure; 7.6-support structure; 8-upper cover plate, 9-filter, 10-bracket; 10.1 — a first accommodation space; 10.2-a second accommodation space; 10.3-a third accommodation space; 10.4-wiring extension mounting holes; 10.5-receiving the extension mounting hole; 10.6-main beam; 10.7-main stringer; 10.8-auxiliary beam; 10.9-auxiliary stringer; 11-a radome; 12-a vibration damping structure; 12.1-damping pad; 12.2-screws; 13-signal processing extension printed board; 14-signal processing extension support; 15-test interface cover plate; 16-debug interface cover plate.

Detailed Description

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and together with the description, serve to explain the principles of the invention and not to limit the scope of the invention.

Meanwhile, how to realize the conformality of the Doppler radar and the mounting surface is considered, the required mounting space is reduced as much as possible, the miniaturization of the Doppler radar is realized, and the testability and the test reliability of the miniaturized Doppler radar which can be conformal to the mounting surface are ensured.

The Doppler radar has a structure conformal with the installation surface, and all the branches of the Doppler radar are arranged in a cavity of the conformal structure. Conformal structure includes main body frame 7 and upper cover plate, main body frame is both ends open-ended tubular structure, and tubular structure's both ends are located respectively to radar antenna house and upper cover plate, and main body frame and antenna house all are conformal with the mounting surface.

The internal cavity of the body frame 7 is used for accommodating the radar body; the radar main body comprises an antenna extension 1, a transceiving component 2, a receiving extension 3, a signal processing extension 4, a wiring extension 5 and a power supply extension 6; the radar main part adopts the extension stacked structure of modularized design, and antenna extension 1, receiving and dispatching subassembly 2, receipt extension 3, signal processing extension 4, wiring extension 5, power extension 6 are the box body structure, adopt the mode that the extension stacked to stack up each extension box body and set up in the inside cavity of main body frame 7.

Specifically, the internal cavity of the main body frame of the conformal structure can be a multilayer structure, and each layer of cavity structure divides a plurality of partitions according to the structure and the number of the arranged extension box bodies. More specifically, the internal cavity of the main body frame is of a 3-layer structure and comprises an upper layer, a middle layer and a lower layer, and the antenna extension occupies the lower layer independently; the filter, the power extension and the transceiving component are positioned in the middle layer; the receiving extension, the wiring extension and the signal processing extension are positioned on the upper layer. More specifically, the signal processing extension is arranged in the one side region on upper strata alone, it is regional with the opposite side of extension of working a telephone switchboard parallel arrangement on upper strata to receive the extension, the power extension is located between wave filter and the receiving and dispatching subassembly, the receiving and dispatching subassembly is located the below of extension of working a telephone switchboard and signal processing extension, the power extension is located the below of the receipt extension of upper strata, the lower surface of receiving the extension is equipped with the cavity structure, the extension of working a telephone switchboard is located the cavity structure of the receipt extension between receipt extension and the power extension.

The passive extension is adopted as the antenna extension, power supply is not needed, the reliability is very high, maintenance is basically not needed after the antenna extension is qualified through testing, and the antenna extension is placed at the bottommost layer; arranging the filter, the power supply extension and the transceiving component in the same layer above the antenna extension to form a middle layer, and arranging the filter and the power supply extension at positions close to the external interface of the radar; arranging the receiving branch, the wiring branch and the signal processing branch in the uppermost space of the conformal structure at the upper part of the middle layer to form the uppermost layer, and arranging the signal processing branch at the outermost position; the wiring extension adopts a single printed board to connect signals between the signal processing extension, the transceiving component and the radar console, each extension adopts a box structure to realize modularization, technical means such as a lap joint mode are adopted between the antenna housing and the main body frame, so that the wiring and signal testing is facilitated, the mutual influence between the radar extensions and the electromagnetic shielding capability to the outside are improved, and the testability of the miniaturized Doppler radar is improved.

The invention provides test convenience and reliability of a miniaturized Doppler radar by adopting a design idea of combining selection of a conformal structure and extension sets, a form of the extension sets and arrangement of the extension sets, so that the invention provides a method for improving the testability of the miniaturized Doppler radar, the miniaturized Doppler radar has a structure conformal with an installation surface, and each extension set of the Doppler radar is arranged in a cavity of the conformal structure, and the method comprises the following steps:

(4) arranging a modularized filter, a power supply extension and a transceiving group frame which are qualified in test above the antenna extension;

(7) and (6) carrying out a complete machine test.

The method can realize the integral test of the radar main body consisting of all the extension sets in the conformal structure without unpacking. Moreover, the test of the miniaturized Doppler radar arranged in the conformal structure can meet the test requirements of the whole process of a design stage, an assembly stage and a flight stage, and the test before delivery of the Doppler radar can be completed by adopting a radio frequency signal source for testing in a simulated assembly state and a simulated flight state; the built-in self-checking test is adopted to finish the test after the delivery and the setting of the Doppler radar, and the testability of the miniaturized Doppler radar is obviously improved.

In addition, each extension adopts a modular structure, is independent in function, can be separated from the interface equipment to test and check the extension, and greatly improves the testability of the radar. Maintenance and debugging work is not needed after replacement, a special tool is not needed when the device is disassembled and installed, and the replacement time is short. A plurality of test points can be arranged on the wiring extension, and the test points on the wiring extension can be tested only by opening the shell of the whole machine during inspection or maintenance through the plurality of test points of the wiring extension; if the receiving extension or the signal processing extension needs to be replaced, other extensions can be not detached or moved, and visual access can be achieved; the shielding box body of the upper cover plate of the Doppler radar and the signal processing extension is opened, the control core of the Doppler radar can be clearly seen, so that the comprehensive detection of the Doppler radar is completed, the entity can be reached, and the testability of the equipment is greatly improved.

Example 1

The invention adopts the design idea of combining the conformal structure and the selection of the extension, the form of the extension and the arrangement of the extension to realize the conformal of the Doppler radar and the installation surface, the small required installation space (namely miniaturization), and improve the test convenience and the reliability of the Doppler radar.

Specifically, this embodiment provides a method for improving testability of a doppler radar, where the doppler radar has a structure conformal to a mounting surface, and each subset of the doppler radar is disposed in a cavity of the conformal structure, and the method includes the following steps:

the radar main part includes antenna extension 1, receiving and dispatching subassembly 2, receives extension 3, signal processing extension 4, wiring extension 5, power extension 6, and antenna extension, receiving and dispatching subassembly, receiving extension, power extension all can design into the box body form, arrange the box body installation inside the cavity of main part frame. Before each extension is placed into the box body, performance test is carried out to see whether the extension is intact or not, and whether the performance requirements can be met or not can be met.

Specifically, in each extension of the doppler radar, the antenna extension can adopt a waveguide flat plate slotted array to fix the antenna, adopts a receiving and transmitting common single antenna mode, and consists of a plurality of thin-wall aluminum waveguides with slots on narrow sides, a feed waveguide, a waveguide coaxial converter and an absorption load. And is mounted on the main body frame through screws and cylindrical pins. As shown in fig. 3. The antenna extension 1 is close to the antenna housing 11, is separately arranged in the lower cavity of the main body frame 7, and is mounted on the main body frame 7 through screws and cylindrical pins.

The transceiving component 2 consists of a transmitting unit and a receiving unit, wherein the transmitting unit consists of a constant temperature crystal oscillator, a phase-locked medium oscillator, an amplifier, a coupler, an attenuator, a PIN modulator, a power amplifier, an isolator, a circulator, a radio frequency SP4T switch and a mismatch load; the receiving unit is composed of a double-balanced mixer, a cavity filter, an amplifier, an image rejection mixer, a low-noise amplifier, a PIN switch, an isolator and a low-noise intermediate amplifier. The transceiving component 2 is arranged in the middle layer cavity of the main body frame 7 and is installed on the whole main body frame 7 through screws. The constant temperature crystal oscillator in the receiving and dispatching subassembly is sensitive to the vibration environment, for reducing the influence of vibration environment to extension performance, adopts damping structure 12 to carry out the damping in the extension outside, as shown in figure 4, the four corners position of receiving and dispatching subassembly 2 sets up 4 damping structure 12, has avoided the worsening of phase noise under the vibration condition. Through a large amount of mechanical analysis and experimental verification, the phase noise index under the vibration condition of the transceiving component meets the requirement of the system index.

The receiving extension 3 is composed of two-stage AGC intermediate frequency amplifier, isolation amplifier, filter, mixer, AGC low frequency amplifier, low pass filter, self-checking circuit and the like. The main function of the system is to amplify, filter, perform second detection and low frequency amplification on the intermediate frequency signal output by the transceiving component and output a low frequency echo to the signal processing extension; when a self-checking instruction exists, the self-checking circuit works to realize closed-loop self-checking. Fixed on the bracket by screws. In order to realize the modular design of the inside of the receiving extension set 3 and the mutual isolation of the modules, the receiving extension set 3 adopts a box body structure, the box body structure is divided into a plurality of independent cavities 3.1 by a partition plate 3.2, wire passing through holes 3.4 are reserved between the cavities 3.1, the size of each independent cavity 3.1 is arranged according to the installed functional components, as shown in fig. 5 to 6, the box body structure is provided with 4 independent cavities 3.1, and the partition plate 3.2 is provided with the wire passing through holes 3.4. In order to realize the weight target of the whole machine, a plurality of weight reduction grooves 3.3 are arranged on the side wall of the box body structure, so that the weight of the receiving extension 3 is smaller than the pre-distribution weight. In order to realize the modular design of the interior of the receiving extension and the mutual isolation among modules, the receiving extension adopts a box body structure, the box body structure is designed into 4 independent cavities, and round holes for cables are reserved among the cavities.

The power supply extension 6 consists of a power supply module and a power supply filtering module and is used for converting voltage on the carrier into power supply voltage used by each extension in the radar. As shown in fig. 7. The power extension 6 is fixed on the bracket 10 through screws.

The signal processing extension 4 is used as an important component of the Doppler radar, directly influences the performance of the Doppler radar, completes the functions of acquisition, sampling filtering, spectrum analysis and the like of echo signals, and performs vibration reduction design and thermal design. The vibration reduction device is large in area and is a multilayer printed board, vibration reduction is carried out on the signal processing extension during design for solving the characteristic that the vibration resistance of the printed board is weak, a rubber vibration absorber is adopted, the vibration reduction efficiency exceeds 60%, and the vibration response of the printed board is greatly reduced. By adopting the rubber vibration reduction structure 12, as shown in fig. 8, the signal processing extension printed boards 13 are fixedly arranged on the signal processing extension support 14, the signal processing extension support 14 is arranged on the main body frame 7 through the vibration reduction structure 12, the number of the vibration reduction structures 12 is 4, the vibration reduction structures are arranged at four corners of the signal processing extension support 14, the vibration reduction efficiency exceeds 60%, and the vibration response of the signal processing extension printed boards 13 is greatly reduced. The signal processing branch 4 adopts natural convection and radiation heat dissipation

The wiring extension is a single printed board, and is arranged for facilitating wiring and signal testing and used for signal connection of switching signal processing and receiving and transmitting components, signal processing and signal connection of a radar console and the like. The wiring extension consists of a printed circuit board, a connector and a connecting cable.

in order to facilitate wiring and testing, the antenna extension adopts a passive extension, power supply is not needed, the reliability is very high, and the antenna extension basically does not need to be maintained after passing the test, so the antenna extension is placed at the lowest layer, namely the antenna extension 1 is close to the antenna housing 11 and is independently arranged at the lower layer; and the error prevention is realized through the positioning pin and the frame.

filter 9, power extension 6, receiving and dispatching subassembly 2 arrange in the intermediate level on antenna extension 1, and power extension 6 is located between filter 9 and the receiving and dispatching subassembly 2, and power extension 6, filter 9 are close to the radar external interface, are favorable to shortening to filter 9, power extension 6 cable length to the external connector.

the receiving branch machine 3, the wiring branch machine 5 and the signal processing branch machine 4 are arranged on the upper layer, the upper layer is divided into two areas, the signal processing branch machine 4 is independently arranged in one side area of the upper layer, the receiving branch machine 3 and the wiring branch machine 5 are arranged in the other side area of the upper layer in parallel, and the signal processing branch machine 4 is arranged on the outermost side of the inner cavity of the main body frame 7; the extension connector 5 is located in a gap of the receiving extension 3 between the receiving extension 3 and the power supply extension 6 in the middle layer. The wiring extension 5 is close to the radar external interface, which is beneficial to shortening the cable length from the external connector to the wiring extension 5, and also facilitates the cable connection of the wiring extension 5 with the receiving extension 3, the receiving and transmitting assembly 2 and the signal processing. The signal processing extension 4 is a component with the most complex function of the Doppler radar and the most concentrated electronic circuit, is the core for controlling the work of the Doppler radar, is arranged at the outermost side, and can be adjusted by opening a shielding box cover of the extension only by using a screwdriver, thereby being beneficial to the overhaul and test of the signal processing extension 4 when necessary;

the seam adopts the overlap joint form between upper cover plate, antenna house and the main body frame to through the screw fastening, the effectual continuous metal contact of box body of having guaranteed reaches electromagnetic shield's efficiency, has also improved miniaturized Doppler radar's testability.

(7) And (6) carrying out a complete machine test.

On the whole, the layout mode of each extension of the radar is as follows: the antenna extension 1 is close to the antenna housing 11 and is separately arranged at the lower layer; the filter 9, the power supply extension 6 and the transceiving component 2 are arranged in the middle layer above the antenna extension 1; the receiving branch 3, the wiring branch 5, and the signal processing branch 4 are disposed on an upper layer. The upper layer is divided into two areas, the signal processing extension set 4 is independently arranged in one side area of the upper layer, the receiving extension set 3 and the wiring extension set 5 are arranged in the other side area of the upper layer in parallel, and the signal processing extension set 4 is arranged on the outermost side of the inner cavity of the main body frame 7; the power supply extension 6 of the middle layer is positioned between the filter 9 and the transceiving component 2, the transceiving component 2 of the middle layer is positioned below the wiring extension 5 and the signal processing extension 4, the power supply extension 6 of the middle layer is positioned below the receiving extension 3 of the upper layer, the wiring extension 5 is positioned in a gap of the receiving extension 3 between the receiving extension 3 and the power supply extension 6 of the middle layer, and the power supply extension 6, the filter 9 and the wiring extension 5 are close to an external radar interface; the transceiving component 2 arranged on the lower layer is positioned below the signal processing extension 4, the front panel for installing the transceiving component 2 is slotted, and the cable is detached and installed through a slotted opening on the panel.

Compared with the prior art, the Doppler radar layout structure that this embodiment provided, with Doppler radar complete machine structure modularized design, establish main body frame 7's inside cavity structure into 3 layers of structure, adopt extension stacked structure to be favorable to each extension assembly, test, wiring and maintenance. The antenna extension 1 is a passive extension, does not need power supply, has very high reliability, basically does not need maintenance after passing the test, and is placed at the lowest layer. The transceiving component 2 communicates and controls with the antenna extension 1 and the wiring extension 5 through radio frequency cables and low frequency cables, and the transceiving component 2 is arranged on the upper layer of the antenna extension 1 to be most beneficial to cable connection and assembly. The power extension 6, the filter 9 and the wiring extension 5 are close to the radar external interface, which is beneficial to shortening the cable length from the external connector to the filter 9, the power extension 6 and the wiring extension 5, and also facilitates the cable connection of the wiring extension 5 and the receiving extension 3, the transceiving component 2 and the signal processing. The signal processing extension 4 is a component with the most complex function of the Doppler radar and the most concentrated electronic circuit, is the core for controlling the work of the Doppler radar, is arranged at the outermost side, and can be adjusted by opening a shielding box cover of the extension only by using a screwdriver, thereby being beneficial to the overhaul of the extension; for the high frequency cable of receiving and dispatching subassembly 2 of easy to assemble, the place ahead panel at installation receiving and dispatching subassembly 2 has carried out the fluting design, and the dismantlement and the installation of cable have been carried out to the accessible fluting mouth, have made things convenient for the installation of complete machine.

After the radar is assembled, performance test can be carried out, and the method can realize the integral test of the radar main body consisting of all the extension sets in the conformal structure without unpacking. Moreover, the test of the miniaturized Doppler radar arranged in the conformal structure can meet the test requirements of the whole process of a design stage, an assembly stage and a flight stage, and the test before delivery of the Doppler radar can be completed by adopting a radio frequency signal source for testing in a simulated assembly state and a simulated flight state; the built-in self-checking test is adopted to finish the test after the delivery and the setting of the Doppler radar, and the testability of the miniaturized Doppler radar is obviously improved.

When the radio frequency signal source is tested, the mismatch load is taken down, and the transmitting signal is input to the signal source through the cable connection. The self-checking mode in the machine is different from the working state under the condition of discontinuous continuous waves because the time delay of the signal reflected back by the mismatched load relative to the transmitted signal is very small. The radio frequency signal source can simulate the time delay, Doppler frequency and echo signal power of the echo signal by adopting a radio frequency storage technology, and can complete the functional test of the radar in a discontinuous continuous wave state.

When a self-checking instruction exists, the switch is connected with the mismatched load, a signal transmitted by the radar reflects a part of signal back to a receiving branch after passing through the mismatched load, meanwhile, a local oscillation signal in the intermediate frequency receiver is switched to an FM + Fd signal, an Fd signal is generated after frequency mixing, the frequency difference is used as Doppler frequency, the frequency of the Fd is detected by signal processing, and if the frequency and the amplitude of the signal are within a certain tolerance range, the radar is normal. The method can detect functional unit modules except the antenna extension and the high-frequency cable between the antenna and the transceiving component, key algorithms such as software flow, Doppler frequency estimation and the like can be detected, and key functions of tasks can be monitored by BIT. The antenna extension after test and screening and the high-frequency cable between the antenna extension and the transceiving component have stable performance indexes, and can not be detected any more during self-detection in the machine, thereby achieving the box-opening-free test.

The built-in self-test can detect all functional modules except the antenna extension and the high-frequency cable between the antenna extension and the transceiver component, key algorithms such as software flow, Doppler frequency estimation and the like can be tested, and key functions of tasks can be monitored by BIT. Under the ground and flight states, the Doppler radar can perform reliable self-checking and returns to a guidance computer in a state word form, so that the failure fault part of the Doppler radar can be clearly judged.

By adopting the method, the miniaturized Doppler radar meeting the requirements of performance and indexes can be obtained. The test result shows that: the self-checking in the machine can display parameters such as radar status words, fault codes, triaxial velocity values and the like, and can display parameters such as signal-to-noise ratio, AGC voltage, frequency values and the like when a radio frequency signal source is tested.

In order to better improve the testability of the miniaturized doppler radar, the following aspects can be considered:

1. the aspect of suppressing electromagnetic interference sources: the method has the advantages that the shielding technology is adopted, the influence of interference source radiation on the reliability of the radar system is reduced, the shielding boxes are adopted for each extension, the extensions are arranged in a multilayer mode, high-shielding cables can be adopted for signals with high power, connecting lines among the extensions can bypass areas with strong radiation as far as possible, shielding arrangement is adopted for clock lines in circuits, and the like are far away from sensitive circuits;

2. besides reasonably arranging the dividers, the following measures can be adopted to improve the electromagnetic shielding capability of the radar: the suppression degree of the high-frequency front end to the image frequency is improved; the bandwidth of the intermediate frequency amplifier is designed according to the optimal matching receiving principle, the occupied bandwidth is minimum, the optimal signal to noise ratio is obtained, and the electromagnetic interference sensitivity threshold of the receiver is improved; the power supply input ends of the extension sets are provided with EMI filter circuits, so that EMI interference conducted among the extension sets through power lines is reduced; the power supply circuit in each extension is provided with a power supply filter circuit to isolate the conducted interference in the line; the working power supply input end is provided with a special power supply filter and a power supply spike interference suppression circuit, so that interference introduced by an input power supply is reduced; each combined power supply is provided with a decoupling filter, so that the electromagnetic compatibility performance is improved; the bus adopts a coupling mode of transformer isolation, and the signal adopts a special shielding cable with specific impedance, so that the electromagnetic shielding capability in flight is improved, the external electromagnetic influence is reduced, and the testability and the test reliability are improved;

3. in the design of radar electromagnetic compatibility, the grounding system is reasonably designed, so that the requirements of the system on shielding and filtering can be reduced, and the electromagnetic compatibility of the radar can be improved. The concrete measures are as follows: the radar is assembled in time after being cleaned by an aluminum cleaning agent when the sub-systems, the panel and the bottom plate of the radar are installed, so that a good ground passage is formed; (2) the radar is designed separately from the analog ground in a digital mode and is connected in a single point; (3) in circuit design, copper-clad or multi-ground planes are used as much as possible.

Example 2

This embodiment describes in detail a conformal structure for realizing the conformity of the doppler radar with the mounting surface, and the arrangement of the doppler radar in the conformal structure, so as to facilitate understanding of the method for improving the testability of the small doppler radar of embodiment 1.

Firstly, the doppler radar is conformal to the installation surface, as shown in fig. 2 and fig. 9-10, the conformal structure includes a main body frame 7 and an upper cover plate 8, the main body frame 7 is a cylindrical structure with two open ends, and an internal cavity of the main body frame 7 is used for accommodating the radar main body; the upper cover plate 8 is arranged at the upper end of the cylinder structure, the periphery of the lower end face of the cylinder structure is provided with a convex edge 7.1, and the surface of the convex edge 7.1 is conformal with the installation face of the aircraft; the mode that adopts extension to pile up is piled up each extension box body and is set up in main body frame 7's inside cavity.

The conformal structure of the Doppler radar further comprises a lower cover plate, the lower surface of the lower cover plate is conformal with the installation surface of the aircraft, and the lower cover plate is assembled with the convex edge 7.1 of the main body frame 7 to form a conformal surface matched with the installation surface of the aircraft.

In this embodiment, the conformal structure further includes an antenna housing 11, the antenna housing 11 and the lower cover plate are independently arranged, the independently arranged antenna housing 11 is conformal with the lower cover plate, and the antenna housing 11 and the lower cover plate are conformal with the aircraft mounting surface; alternatively, the radome 11 is used in place of the lower cover plate, with the outer surface of the radome 11 conforming to the aircraft mounting surface. The conformal structure appearance of Doppler radar adopts the box body form, and the seam adopts the overlap joint form and passes through the screw fastening between upper cover plate 8, antenna house 11 and complete machine main part frame 7, and the effectual continuous metal contact of box body of having guaranteed reaches electromagnetic shield's efficiency.

In the technical scheme of replacing the lower cover plate with the radome 11, the main body frame 7 is a cylinder structure with two open ends, an internal cavity of the cylinder structure is a space for accommodating a radar main body, the upper cover plate 8 is fixed at the upper end of the cylinder structure of the main body frame 7 through screws, a convex edge 7.1 is arranged on the periphery of the lower end surface of the cylinder structure, the lower surface of the convex edge 7.1 is conformal with an aircraft mounting surface, the convex edge 7.1 arranged on the lower end surface of the cylinder structure is a flange frame integrally formed with the upper part of the cylinder structure, namely a flange frame integrally formed with the cylinder structure is arranged on the outer edge of one end of the cylinder structure along the circumferential direction, the outer surface of the flange frame is an arc surface conformal with the aircraft, a step for mounting the conformal radome 11 is arranged on the inner edge of the flange frame, the lower surface of the radome 11 is conformal with the aircraft mounting surface, the radome 11 is fixedly mounted on the flange frame, the radome 11 forms a part of the conformal structure of the doppler radar, the radome 11 is conformal with the aircraft, the radome 11 is conformal with the radar, the radar is conformal with the aircraft, and the conformal structure is not only the radar main body frame 7, but also the shell of the radar complete machine.

In this embodiment, install the sealing washer between the protruding edge 7.1 of antenna house 11 and body frame 7, the sealing washer is the rubber circle, realizes sealing between antenna house 11 and the body frame 7, can prevent when conformal with the aircraft that water or foreign matter from getting into in aircraft and the aircraft.

For the convenience of installation and the reduction of the use space of the radar, the cylinder structure of the main body frame 7 and the corners of the flanges are rounded.

In this embodiment, the side wall of the cylinder of the main body frame 7 is provided with a plurality of wiring holes and mounting holes, the convex edge 7.1 of the main body frame 7 is provided with a plurality of frame mounting holes 7.3, and the main body frame 7 is fixed on the aircraft mounting surface by screws. The side wall of the main body frame 7 barrel is also provided with a test interface 7.4 for testing in the development process and a debugging interface for debugging, and is provided with a test interface cover plate 15 and a debugging interface cover plate 16 in a matching way, as shown in fig. 9-10.

In order to facilitate accurate and rapid installation and positioning of the main body frame 7 and the upper cover plate 8, as shown in fig. 10, the top end of the main body frame 7 is provided with a limiting structure 7.5, the lower end of the upper cover plate 8 is provided with a limiting matching structure, and the limiting structure 7.5 is matched with the limiting matching structure to fix the upper cover plate 8 at the end part of the main body frame 7. Exemplarily, the limiting part is a first notch arranged on the upper end surface of the main body frame 7, a first protrusion arranged on the bottom surface of the first notch, the limiting matching structure is a second protrusion arranged on the lower surface of the upper cover plate 8, the second protrusion is matched with the first notch on the upper end surface of the main body frame 7, and the second protrusion is provided with a second notch matched with the first protrusion on the bottom surface of the first notch on the surface. This structural arrangement can facilitate accurate, quick installation and positioning of the main body frame 7 and the upper cover plate 8.

In order to realize accurate and reliable positioning between the conformal structure and the aircraft, a plurality of positioning mounting holes are formed in the periphery of the lower end face of the cylinder structure, as shown in fig. 10, when the periphery of the lower end face of the cylinder structure is provided with a convex edge 7.1, a positioning pin hole 7.2 is formed in the convex edge 7.1, a main body frame 7 is correspondingly provided with a positioning pin hole 7.2, a positioning pin penetrates through the positioning pin hole 7.2 to fix and position the main body frame 7 and the aircraft, and the positioning pin hole 7.2 is located on an axial central line of a horizontal beam angle position of the doppler radar antenna. Through the structural design that the designated position sets up locating pin hole 7.2 on main body frame 7 protruding edge 7.1, not only can guarantee the positioning accuracy of doppler radar main part in conformal structure, can also realize the error-proofing installation.

Compared with the prior art, the Doppler radar layout structure provided by the embodiment adopts the structural layout design that the radar is conformal to the aircraft and the extension is conformal to the whole machine, the radar is compact in structure, small in size, small in space and high in speed measurement precision, the structural technology installation precision requirement associated with the navigation technology performance is met, the structural electromagnetic shielding design is also met, the physical shielding electromagnetic wave can be achieved, and the reliability and the electromagnetic compatibility of the product are effectively improved. In addition, the lower end of the upper cover plate 8 is provided with a limit matching structure through the limit part arranged on the main body frame 7 to ensure the positioning precision of the conformal structure and the aircraft, the structural design of the positioning hole formed on the convex edge 7.1 ensures the positioning precision of the Doppler radar main body in the conformal structure, the positioning precision of the Doppler radar is realized through the special design of the conformal structure, and the working performance of the Doppler radar is ensured.

In addition, consider that the aircraft is at the flight in-process, the vibration environment that the doppler radar bore is more great, the operating condition of signal processing extension 4 and receipt extension 3 in the current doppler radar host computer is not suitable for the vibration environment of aircraft flight, therefore, pass through damping structure 12 with each extension box body and fix on main body frame 7, each extension box body is equipped with the extension box body mounting hole that is used for installing damping structure 12, damping structure can avoid extension box body and main body frame 7 direct collision, in order to reduce the vibration injury, it is concrete, pass through damping structure 12 with number processing extension and receiving and dispatching subassembly 2 and fix on main body frame 7, install damping structure 12 additional for signal processing at the inside vertical direction of radar complete machine, install damping structure 12 additional for receiving extension 3 at the horizontal direction. As shown in fig. 8, 13 and 14.

Illustratively, the vibration damping structure 12 includes the following two structures: a damping structure includes screw, two damping pad and two metal gasket, and damping pad and metal gasket homoenergetic overlap and establish on the screw, and the damping pad is the boss structure, including first section and second section, the external diameter of first section is less than the external diameter of second section, and the external diameter of first section equals the aperture of extension box body mounting hole, and first section is equipped with the through-hole that allows the screw to pass, and the aperture and the screw rod diameter of through-hole equal. When the vibration reduction box is used, a first metal gasket and a first vibration reduction pad are sequentially installed on a screw, a second section of the first vibration reduction pad is in contact with the first metal gasket, the screw penetrates through the installation hole of the extension box body, a second vibration reduction pad and a second metal gasket are sequentially installed at the threaded end of the screw, the first sections of the first vibration reduction pad and the second vibration reduction pad are oppositely arranged and are respectively inserted into two ends of the installation hole of the extension box body, the screw is screwed into the screw hole of the main body frame, and the fixed connection of the extension box body to be subjected to vibration reduction and the main body frame is completed.

The second vibration damping structure comprises a steel pipe core, two vibration damping pads, a metal gasket and a screw, wherein the steel pipe core is of a T-shaped structure, a baffle plate is integrally formed on the outer edge of the first end of the steel pipe core, and the vibration damping pads and the metal gasket can be sleeved on the steel pipe core; the damping pad is the boss structure, including first section and second section, and the external diameter of first section is less than the external diameter of second section, and the external diameter of first section equals the aperture of extension box body mounting hole, and first section is equipped with the through-hole that allows the steel pipe core to pass, and the aperture of through-hole equals with the external diameter of steel pipe core. During installation, earlier establish first damping pad cover and install on the steel-pipe core, make the separation blade contact of the second section of first damping pad and the first end of steel-pipe core, pack the second end of steel-pipe core into extension box body mounting hole, wear out the part of extension box body mounting hole at the steel-pipe core and establish installation second gasket and metal gasket in proper order, wherein, the first section of second gasket is towards extension box body mounting hole, the first section of first damping pad and second damping pad sets up relatively and inserts the both ends of extension box body mounting hole respectively, penetrate the screw hole on the screw from the second end of steel-pipe core and twist into the main body frame, accomplish and treat damping extension box body and main body frame's fixed connection. Compare with first kind and subtract battle array structure, second kind damping structure sets up the separation blade through edge integrated into one piece outside the top at the steel-pipe core, has reduced part quantity, and it is more convenient to install, and the installation effectiveness is higher, and the damping effect is better. In this embodiment, the damping pad of damping structure 12 is made by the rubber material, and the damping pad sets up a plurality of damping holes, and the damping effect is better.

In this embodiment, fix each extension box body on main body frame 7 through damping structure 12, set up the damping pad into boss structure, avoid extension box body and main body frame 7 direct collision, show the damping and come from the vibration injury of the vertical direction and the horizontal direction of installation face, make better adaptation operational environment of radar, improve doppler radar electromagnetic shield ability, measurement accuracy and reliability.

Compared with the prior art, the Doppler radar layout structure that this embodiment provided adopts the modularized design, with antenna extension 1, receiving and dispatching subassembly 2, receipt extension 3, signal processing extension 4, wiring extension 5, power extension 6 all set up to the box body structure, adopts the mode that the extension piled up to pile up each extension box body and sets up in main body frame's inside cavity, makes Doppler radar's overall structure compacter, and integrated level is higher, each extension assembly, test, wiring and the maintenance of being convenient for. Through fixing each extension box body on main body frame 7 through damping structure 12, avoid extension box body and main body frame 7 direct collision, can show the damping and come from the vibration injury of installation face, make better adaptation operational environment of radar, improve doppler radar electromagnetic shield ability, improve the accuracy and the reliability of test.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Claims

1. A method of improving the testability of a doppler radar having a structure conformal to a mounting surface, each extension of the doppler radar being disposed within a cavity of the conformal structure, the method comprising the steps of:

(7) and (6) carrying out a complete machine test.

2. The method according to claim 1, wherein in the step (3), the antenna extensions are passive extensions, and are placed on the bottommost layer without power supply.

3. The method of claim 2, wherein in step (4), the filters, the power extension and the transceiver component are arranged in the same layer above the antenna extension to form an intermediate layer, and the filters and the power extension are arranged at a position close to the external interface of the radar.

4. The method of claim 3, wherein in step (5), the receiving extension, the wiring extension, and the signal processing extension are disposed in an uppermost space of the conformal structure above the intermediate layer, forming an uppermost layer, with the signal processing extension disposed in an outermost position.

5. The method of claim 4, wherein in step (5), the extension switchboard connects signals between the signal processing extension, the transceiver component and the radar console by using a single printed board.

6. The method of claim 1, wherein in step (7), the radar body comprised of extensions within the conformal structure is tested in its entirety.

7. The method according to claim 1, wherein in the step (1), the conformal structure comprises a main frame and an upper cover plate, the main frame is a cylindrical structure with two open ends, the radome and the upper cover plate are respectively arranged at two ends of the cylindrical structure, and both the main frame and the radome conform to the installation surface.

8. The method of claim 7, wherein the radome and body frame overlap.

9. The method according to claim 1-8, characterized in that in step (2), each extension adopts a box structure to realize modularization.